Scouring of Nylon is recommended before any heat-setting, bleaching, or dyeing processes are performed on the goods. Scouring will remove any excess oils, waxes, lubricants, or general soil that may be left in the fiber after manufacture, handling, storage, etc. For the most part nylon preparation consists of scouring with detergents which may consist of nonionic ethoxylates or anionic detergents in conjunction with various builders, sequestrants and alkali to remove contaminants as described above. Nylon containing graphite , such as lace, should be scoured before storage as graphite becomes more difficult to remove over time.
In addition to the general scouring, nylon is sometimes whitened as a base for pastel shades or even optically brightened. This may be performed after scouring or as one step during the scouring operation. This whitening is generally achieved through the use of either oxidative or reductive type bleaches. The following represents a typical procedure which would cover 60-70% of the normal requirements.
- Enter goods into a bath at 100°F(38°C) and add:
0.50-1.00 % owg Orconol CHSA Conc™
0.10-0.20 % owg Soda Ash to pH of 8.0-9.0
0.25-0.50 % owg Orcopon PCA™ (This may be increased to 1-2% owg for heavy graphite contamination.)
0.10-0.20 % owg Sodium Hexametaphosphate
- Raise temperature of bath to 120°F(49°C) and run 2 ends.
- Raise temperature to 150°F(66°) and run 2 additional ends.
- Drop bath and run 2 rinse ends at 120°F(49°C).
- Drop rinse bath and refill, running 2 additional running rinses (overflow). Proper rinsing is important so that no contaminates or residual detergent is carried over into the dye cycle.
- Check pH and acidify if necessary.